Drum and single shoe brake



Aug. 10, 1954 F. E. BACHMAN DRUM AND SINGLE SHOE BRAKE -2 Sheets-Sheet 1 Filed July 22, 1950 E INVENTOR. 2 5194; Zfiac/ifizm Aug. 10, 1954 F. E. BACHMAN 2,685,942

DRUM AND SINGLE SHOE BRAKE Filed July 22, 1950 2 Sheets-Sheet 2 Patented Aug. 10, 1954 UNITED STATES TENT OFFICE DRUM AND SINGLE" SHOE BRAKE Application July 22, 1950, Serial No. 175,460

12 Claims.

This invention relates to brakes and more particularly to a novel railway brake having unusual capacity to decelerate trains moving at high speeds. 4

Aprimary object of the invention is todevise a drum type railway brake wherein brake bands engageable with the drum are supported by the frame of a railway car' truck.

Another object of the invention isto accommodate vertical movements of the supporting truck frame without moving the bands.

A further object of the invention is to devise novel supporting and torque transmitting means for the brake bands.

A different object of'the invention is to devise novel actuating means for the brake bands capable of applying them under substantially equal pressure to the drum.

Another object of the invention is to devise a brake actuating system for simultaneous actuation of a drum brake and a wheel tread brake.

Still another object of the invention is'to devise a novel brake drum having a readily removable friction shell mounted on its outer perimeter for engagement with associated brake bands.

The foregoing. and other objects and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawings wherein:

Figure 1 is a top'plan view of a railway car truck embodying the invention, only'one-ha'lf of the truck being shown, inasmuch. as'the brake system is identical at opposite sides thereof;

Figure 2 is a side elevational view of the left half of the truck shown in Figure 1;

comprises a truck frame, generally designated 2,

supported in conventional manner by springs diagrammatically indicated'at 4, in Figure 5, said springs being mounted on an equalizer 6 adjacent theends thereof, which are not shown for the sake of clarity, said ends being supported in 'the usual'manner'by journal'boxes 8 of wheel and axle assemblies generally designated [2. Eachwheeland axle assembly includes an axle it having a wheel is mounted thereon adjacent each end thereof.

As best seen in Figures 3 and 4, a brake rotor or drum, generally designated I1, is connected to the wheel and axle assembly l2 for rotation therewith, as for example by screws l 8 connected to the adjacent wheel l6. Preferably, a sleeve or shell it (Figure 4) is sleeved on the outer perimeter of the drum l1 and is retained within a recess 26 at the outboard edge thereof by a ring 22 having a recess 24 receiving the opposite edge of the shell 19. The ring is removably attached to the drum as by screws 26.

The sleeve i9 is preferably provided with a plurality of spaced friction blocks 28 (Figures 3 and 4:) secured thereto in any desired manner as for example by bonding or rivets (not shown); however, it will be understood'that if desired the blocks 28 may be eliminated and the shell 9 2 may be provided with any desired friction surface.

Associated with each brake drum i? is a pair of brake bands or shoes 36 having lugs 32 pivotally fulcrumed by a pin 34- to an'arm 35 of a support bracket generally designated 33, said arm being removably connected, as for example by screws 46, to another arm-52 which extends outboardly of the adjacent wheel i6 and is connected to the inboard side of the related journal box 8 which, in the illustrated embodiment of the invention,'is cast integral with the arm d2. Thus each brake support frame 38, as best seen in the left half of Figure 1, is generally U-shaped in plan view with the arm 36 projecting inboardly of the adjacent wheel l6 and the arm s2 projecting outboardly thereof, the wheel l6 being received between the arms of the frame 35 to afford a compact brake support structure adapted to afford a sturdy and rugged support within the space limitations inherent in a conventional railway car-truck.

As best seen in Figure 2, and the left half of Figure 1, the armtt is provided with jaws 44 adapted to receive thefulcrum lugs 32 of the brake bands til, said jaws having notches or recesses opening upwardly and adapted to receive loosely the pin 34, which is yieldingly held within the notches 45 by a flat plate spring 43 anchored V by a bolt and nut assembly 50 to the arm 36.

The jaws M are embraced by jaws 52 of a torque arm 54 resiliently and universally connected to a bracket "56 on an adjacent transom 5! of the truck framed by meansof spaced resilient' pads. 58 and a nut 69 threadedon the torque armed to compress' the pads 58 against opposite sides of the bracket 56. The armsiZ are pivotally connected to the pin 34 by openings in said arms, as best seen in Figure 4, said openings receiving the pin 34 and being substantially complementary thereto. Thus it will be seen that the arm 54 aids in the distribution of torque to the sprung frame whereby any tendency of the journal box to bind at its diagonal corners in the related pedestals 62 is alleviated. The torque arm then functions to prevent the journal box from rotating on its axle either due to the off center loading of the support bracket 38 while the brakes are inoperative or to a combination of the off center loading of the support and braking torque when the brakes are operative.

Thus it will be understood that the truck frame 2 is a sprung portion of the truck supported by springs 4 on the unsprung equalizers 6 thereof, and as the frame 2 moves upwardly and downwardly on its supporting springs 4, the torque arm 54 pivots about the pin 34, thereby avoiding vertical displacement of the bands 30 which are supported by the unsprung brake frame 38. In this manner, the brake bands 30 are maintained in concentric relationship with respect to the drum ll. It may be noted that the frame 2 is guided, during such vertical movement, by conventional pedestal legs 62 embracing each journal box 8.

Each brake band 3% is preferably provided on its outer perimeter with a plurality of radial heat dissipating fins t l and is also provided with a pair of actuating lugs or arms 66 above the rotational axis of the wheel and axle assembly 52, the fulcrum lugs 32, as heretofore described, being below said axis.

Wheel brake means are preferably provided for each wheel 55 in the form of a conventional truck lever 88 shown in the illustrated embodiment as a dead truck lever having a fixed pivot at it to the truck frame and a pivotal connection as at E2 to a brake head 14 carrying a conventional brake shoe T6 for engagement with the tread or rail engaging surface of the wheel it. As best seen in Figure 5, each brake head i i is pivoted to the related truck lever 58 by a tie rod ll extending transversely of the truck for similar connection to the corresponding brake head I i and truck lever 68 at the opposite side of the truck.

The above-described brake system is preferably operated by a conventional piston and cylinder device if; actuated in the usual manner by compressed air and comprising a piston rod Bil pivotally connected as at 82 to a live cylinder lever 8 which is pivotally connected intermediate its ends as at 86 to a conventional slack adjuster pull rod 38 having a pivotal connection as at til to a dead cylinder lever 92 intermediate its ends. The dead cylinder lever 92 is pivotally connected as at 96 to a bracket 95 on the end of the cylinder "it remote from the rod Bil.

The inboard end of each cylinder lever is pivotally connected as at 95 to a link 98 having a pivotal connection as at Hi0 to an equalizer link I62. The outboard end of each equalizer link it? is pivotally connected by a ring and clevis ill-i (Figure 1, right) to the upper end of the adjacent truck lever 58, and the inboard end of each equalizer link $62 is pivotally connected by a link and clevis E86 (Figure 3) to the upper end of a live auxiliary lever I08, the lower end of which is pivotally connected as at III! to a compression or push rod H2 pivotally connected as at H4 to the lugs 66 of the adjacent brake band 30.

The live auxiliary lever ms is pivotally connected intermediate its ends as at II6 to a pull rod M8, the opposite end of which is pivotally connected as at I20 intermediate the ends of a dead auxiliary lever I22, the upper end of which is pivotally fulcrumed as at lid to a fulcrum bracket I25 on an end rail I28 of the truck frame 2. The lower end of the dead auxiliary lever I22 is pivotally connected as at I30 to a compression or push rod I32 which is pivotally connected as at I34 to the lugs 6d of the adjacent brake band 33, whereby upon actuation of the brake system, as hereinafter described, the bands 30 clamp the related brake drum I'l therebetween.

It may be noted that the brake cylinder 18 is preferably mounted on a pad 538 on the outboard side of the truck frame 2 in what is known in the art as a unit cylinder arrangement.

Upon actuation of the above-described brake system, the piston rod moves to the left, as shown in Figure 1, thereby rotating the live cylinder lever 84 about its pivot point 85 thereby actuating the brake means associated with the related wheel. Thereupon, the pull rod 838 rotates the dead cylinder lever 92 in a counterclockwise direction about its pivot point 94 to actuate the brake means associated with the other wheel.

It will be understood that upon actuation of each equalizer link I62 by the related cylinder lever, the truck lever 68 associated therewith is operated to urge its shoe '16 against the tread surface of the adjacent wheel, and the associated live auxiliary lever I68, as best seen in Figure 3, is rotated about its pivot point ME to exert a pushing force on the related rod H2, thereby urging one of the brake bands 3i into engagement with the drum II, whereupon pull exerted by the rod I i8 on the dead auxiliary lever I22 is effective to exert a pushing force on the rod it?! to urge the other brake band 3t against the drum Ii. Thus, it will be understood that upon actuation of the power cylinder device '15, Bil, both the wheel and off-wheel brake means of each wheel and axle assembly I2 are actuated to decelerate the truck.

I claim:

1. In a brake arrangement for a railway car truck, a truck frame, a supporting wheel and axle assembly including a journal box, pedestal jaws on the frame receiving said box whereby same is movable vertically relative to said frame, a rotor on the assembly, a torque rod universally connected to the frame and extending beneath the rotational axis of said assembly, a pair of bands pivoted to the rod beneath said assembly and disposed at opposite sides of said rotor, means provided on said box to support said bands, and means connected to said bands for engaging them with said rotor.

2. In a brake arrangement for a railway car truck, a truck frame, a supporting wheel and axle assembly including a journal box, said assembly and box being movable vertically relative to said frame, pedestal jaws on the frame receiving said box, a rotor on the assembly, a brake support carried by said box, an independent torque arm universally connected to said frame and projecting beneath the rotational axis of said assembly, brake bands pivoted to said arm and support beneath said axis to engage said rotor, and actuating means for said bands connected thereto above said axis.

3. In a brake arrangement for a railway car truck having a truck frame and a supporting wheel and axle assembly; the combination of inboard and outboard brake surfaces on said assembly, inboard and outboard brake means for respective surfaces, said inboard brake means including a pair of brake bands supported by said .assembly, torque resisting means universally connecting said bands to the frame, power means supported by said frame, and an operative connection between said power means and both of said brake means for substantially simultaneous actuation thereof.

4. In a brake arrangement for a railway car truck having a truck frame and spaced supporting wheel and axle assemblies; the combination on inboard and outboard brake surfaces on each assembly, inboard and outboard brake means for respective surfaces, said inboard brake means including a pair of brake bands supported by said assembly, torque resisting means universally connecting said bands to the frame, a power cylinder device supported by said frame, live and dead cylinder levers pivotally connected to opposite ends of said power means and pivotally connected to each other, and means operatively connecting each cylinder lever to the inboard and outboard brake means for the adjacent assembly.

5. A brake arrangement, according to claim 4, wherein the connection of each cylinder lever to the related inboard brake means comprises live and dead auxiliary levers pivotally connected to each other and operatively connected to said inboard brake means.

6. In a brake arrangement for a railwaycar truck having a wheel and axle assembly and a truck frame resiliently supported by said assembly; the combination of a U-shaped bracket carried by the assembly and including spaced arms receiving a portion of a Wheel therebetween, a pair of brake bands pivoted to one arm of said support beneath the rotational axis of said assembly, and actuating means for said brake bands connected thereto at the opposite side of said axis.

7. A brake arrangement, according to claim 6, wherein means are provided for transmitting torque from said brake bands to the truck frame.

8. In a brake arrangement for a railway car truck having a wheel and axle assembly and a truck frame spring-supported therefrom; the combination of a bracket carried by said assembly outboardly of a wheel thereof, a pair of brake bands pivoted to said bracket inboardly of said wheel, a torque arm universally connecting said bands to said frame beneath the axis of rotation of said assembly, and operating means for said bands carried by said frame and connected to said bands above said axis. 7

9. In a brake arrangement for a railway car truck, a truck frame, and a supporting wheel and axle assembly movable vertically relative to said frame and including a rotor, a brake support bracket carried by said assembly and having a rod projecting beneath the rotational axis of said assembly, a torque arm connected to said frame and projecting beneath said axis, brake bands to engage said rotor, pivot means interconnecting said bands and arm and rod, and operating means for said bands comprising interconnected live and dead levers, tension rods connecting certain ends of said levers to respective bands, the opposite end of one lever being pivotally fulcrumed to the structure, and power means operatively connected to the opposite end of the other lever.

10. In a brake arrangement for a railway car truck, a truck frame, spaced supporting wheel and axle assemblies; inboard and outboard brake means for each assembly, said inboard brake means including a rotor and a pair of brake bands, interconnected live and dead cylinder levers supported by said frame, certain ends of said levers having operative connections to the inboard and outboard brake means of the respective assemblies, each of said connections comprising an equalizer having an operative connection to the related outboard means and having another connection to the related inboard brake bands, said other connection comprising interconnected live and dead auxiliary levers, tension rods connectingcorresponding ends of said auxiliary levers to the related inboard brake bands, the opposite end of one auxiliary lever being pivotally fulcrumed to the truck frame and the opposite end of the other auxiliary lever being connected to the related equalizer, and power means connected to one of the cylinder levers, the other cylinder lever being afforded a fixed fulcrum to the frame.

11. In a brake arrangement for a railway car truck comprising a wheel and axle assembly having a brake surface thereon and a supported truck structure including sprung and unsprung portions; the combination of a pair of arms connected to respective portions and pivotally connected to each other, a brake mechanism pivotally fulcrumed to both arms at their point of pivotal connection, said point of connection being disposed below the axis of said assembly, and operating means for urging said brake mechanism against the brake surface of said assembly.

12. In a brake arrangement for a railway car truck having a wheel and axle assembly with a brake surface and a supported truck structure with sprung and unsprung portions; the combination of a support member carried by one of said portions and a torque transmitting member carried by the other of said portions, a brake member, means pivotally connecting said members to each other on a common pivotal axis beneath said axle, and operating means above said axle for urging said brake member against the brake surface of said assembly.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 544,936 Shoemaker Aug. 20, 1895 1,236,243 Wilson Aug. '7, 1917 2,299,726 Baselt et al Oct. 27, 1942 2,347,387 Aurien Apr. 25, 1944 2,359,805 Tack Oct. 10, 1944 2,386,907 Pierce Oct. 16, 1945 2,406,408 Tack Aug. 20, 1946 2,413,614 Eksergian Dec. 31, 1946 2,504,712 Mann Apr. 18, 1950 

